On 08/06/2011 06:46, V G wrote:
> 1. Mouser shows several DO-35 zener diodes that are apparently able to
> dissipate 5W. Is this really (safely) possible?
>
> http://ca.mouser.com/Semiconductors/Discrete-Semiconductors/Zener-Diodes/=
_/N-6hpds?P=3D1z0z7uzZ1z0w7s7
>
> 2. Is mounting through hole power components vertically (like in the shap=
e
> of an up side down U) on the PCB better for thermal dissipation?
>
>
> Sorry for duplicating the thread. Forgot to add tag.
1) Maybe, but not wise. At 5W I'd want a heat sinking  arrangement and=20
clever thermal design.. Even a free air TO220 would be pushed for 5W.

2) no, the dissipation depends partly on large copper lands on PCB. The=20
longer leg of U impairs cooling. Body against copper land and copper=20
land on top and bottom sides of PCB.


--=20
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